Force-feed charge-forming device



Julylqwzs] H CUTLER 1.721,209

l l FORCE FEED CHARGE FRMING DEVICE l Filednec. 27 1925 4 sheets-sheet 1lign- July 16, 1929; H. H. c-UTLER FORCE FEED CHARGE FORMING DEVICE IFiled Dec. 27, 1923 4 Sheets-Sheet 2 -July 16, 1929.

H. H. CUTLER FoRcE.FEED CHARGE FORMING'DEVWIGE Fild Dc. 27', 1925 '4Sheets-'Sheet 5,

Patented July 16, 19,29..

v UNITED smiias HENRY H. CUTLER, 0F BROOKLINE, MA's'sACH-SETTS.

FORCE-FEED 'cHARGE-FoRMINeDEvicE.

imputation filednecember 27,1223. serial No. 682,962.

The object of my invention is to'produce a force-feed charge-formingdevice that will deliver to the intake manifold an exceedingly intimatemixture of air and fuel in a correct and uniform proportion, andsurround each minute particle of fuel withsufficient air to make itpossible to produce, when fired, complete combustion or CO2, which is aharmless, non-poisonous gas.

This I accomplish chiefly by forcing the liquid fuel under pressure1around the pef riphery f a comparatively large valvelifted only a fewthousandths of an inch from its seat. For example, this distance in aone inch carburetor may be about .O02 of an inch. The style ofcarburetor which has gone almost into universal use sucks' the fuelaround the surface of a needle valve lifted from its seat a distancefrequently of 1/50 or .02 of an inch, thus delivering` the fuel to themixing chamber in the shape of globules averaging .02 in diameter, orone thousand times the volume of drops .O02 inches in diameter obtainedin my invention.

It has been ascertained experimentally that the large drops of liquidfuel produced in most carburetors hold to their globular form with greattenacity. Y

This means that only the outside circumference oflthesecomparativelylarge dropsof liquid fuel come in contact `with the airfrom which they may derive sufficient oxygen to form CO2 gas when fired,the inside or greater part of these globules not coming in directcontact with the air, cannot Obtain su'ff icient oxygen to form CO2,with the result that the exhaust gases of 'all gasoline enginesuniversally used for propelling automobiles, emit CO gas with theexhaust, which is highly poisonous, besides causing a great loss in theeflioiency of the engine.

The drawings submittedare made full size for a so called one inchcarburetor and while this design may be used in connection with anengine having any number of cylinders,

' it is better, and especially adapted fora four cylinder engine.

Fig. l is a top plan view of a complete charge-forming device embodyingmy invention Fig. 2 is a vertical cross section through the middle of acomplete charge-forming device on line 2-2 of Fig. 1;

Fig, 3 .is a vertical cross's'ection through the middle taken at rightangle to Fig. 2 on line 3 3 thereof;

Fig. 4 is a horizontal section on line 21e-4 of Fig. 2;

' Fig. 7 is a horizontal section on line 7-7 of-Fig. 2;

Fig. 8 is a top plan view of the steering post and control levers of anautomobile; A YF 1g. 9 is a horizontal section on Vline 9-"9 of Fig. 2.Fig. 16 is an elevation partly insection of the Vfront or number onecylinder of a four cylinder, four'cycle engine, having the socalled Thead, and showing applicants charge-forming device attached -thereto.-

VMy charge-formingdevice consists of a main casting 10, cylindrical inshape, tapering gradually towards the top, and provided there with aflange 11 adapted to be bolted to the intake manifold of the engine. Twoprojecting. lugs 12, 12, serve to hold the outside bearing casting 13tothe bowl 10 by means of four screws 14, 14. VThe cylinder Vor bowl 10is turned out smooth inside at 15, 15 'and 16, 16 and a bottom casting17 is turned up to 'fit tightlyin the ybottom of the bowl 10 to whichlitis fastened by the screws 18,.Fig.l 4.

The' bottom `casting V17 has a downward projecting lug 19 which isconnectedwith -fthe outside bearing casting 13 bya .metal bar 20'whichserves to, holdthe castings 10 and 13 rigidly together.

The inside -of the bottom :casting 17 Lis l turned out to fit a steelcylinder 21, whichis threaded on the inside and heldin place by the setscrew 22. Screwed -into this cylinder 21 isa large distributing valve 23which takes the place of the needle valve inmost cari buretors. Thisvalve 23is )ground yaccurately on to a seat formed in the bottom casting17, and isthen partially unscrewedsufheiently to lift lit fromits seat afew-thousandths of an inch. The distributing valve 23 is fastened withscrews 24 to a double conical casting 25. Underneath the valve 23 is asmall cylindrical reservoir26, designed to lhold a small amountof theliquid fuel.

AThree 'circular openings 27, Figs. 2and 4, vare 'cast through the topof the bottom casting 17, which openings connect with va kpassageway 28which can-be opened and closed to any desired amount bymeans o'fthe'butl terfly valve 29 operated by the crank 30.

Another conical casting 31 is also inserted inside the bowl 10, so astofkeep the area of the air passageway the same from the time the airenters through the butterfly valve' 29 until it reaches the intakemanifold through the circular opening 29 in the flange 11. It is thusseen that the suction of the en-y gine will draw the air through thebutterfly valve 29, into the 'passageway 28, thence through thearc-shaped openings 27, and will finally. enter the mixing chamber 32 asa hollow cylinder of air with a very thin wall, shown in the drawings as3/16 of anV inch and tapering toy 3/32 near the top of the mixingychamber. Y

The liquid fuel enters the reservoir 26 through two holes 33, 33,drilled through the bowl 10V and bottom casting 17, after these/.twocastings have been screwed together. i Y

The fuel is'forced into the reservoir 26 Y and thence by the valve 23into the mixing chamber 32 by means of a pair of plunger pumps 34, 34,whose stroke is varied according to the load on the engine. y

The pump plungers are driven by a walking beam 35, fastened rigidly to along hub casting 36, free to'turn on the shaft 37,

i which is supported ateach end by the bowl 10 andthe outside bearingcasting 13 .respectively. Connecting rods 38, 38 connect the pumpplungers and walkingbeam. The hub ycasting 36 has a slotted arm 39projecting at right angles. A square steel block 40 slides freely inthis slot, and is held by a pin 4l, on which it is free to oscillate.r1`hc other end of the pin 41 is fastened rigidly to a forked lever 42by means of the nuts 43, but

can be slid up and down in the slot 44, and thereby adjusted so as tovaryover a wide range the-swing of the walking beam 35 and stroke oftheplungers 34.

The forked lever 42-is rigidly secured to av hub 45, free to oscillateon a pin 46, 'and is 'ven a pendulum movement by means of the disc 47,Figs. 2 and 6, which is fastened by a pin 48 to a shaft 49 driven fromthe engine shaft at preferably the same speed by means -of the sprocketwheels`50, 50 and chain 50.

n The eccentric disc 47 is shown in the drawings as occupying aconcentric position with the driving shaft 49, in which position therotation of the shaft 49 will not cause the i' forked lever 42 tooscillate and there will be `no movement of the walking beam 35 or pumpplungers v34.

vThe mechanical center' of the disc 47, however, can be moved away fromthe center Y of the driving shaft 49 by means of the cylincentric 51. Aslot 52, the same thickness as the pin 48, is milled nearly through thecylinder 51, and then its open end may be closed up with the electricpencilA or otherwise. This cylinder 51 while free to slide on the shaft49, is compelled to rotate with it, without changing its relativeangular position, by means of the pin 48.

It is now seen that as the cylinder 51 is slid along the shaft 49, itwill force the niechanical center of the disc 47 farther and fartheraway from the center of the shaft 49, thereby increasing itseccentricity and setting up a pendulum movement of the forked lever 42and starting the desired de gree of motion of the walking beamA 35 andpump plungers 34.

The movement of the cylinder 51 is controlled by the carriage 53V whichalso slides freely on the shaft 49 as well as 'on the bar 20 which itembraces from rotation. y

The carriage 53 is fastened to a sliding rod 54 which may be connectedwith the throttle lever of an automobile by means of the usual system ofrods and levers, thus giving' the operator complete control ofthe amountof fuel fed to` the engine.l Y

The fuel supply enters kthe intake valve chambers of the two plungerpumps at 62 andk which holds it whence it is drawn through the inletvalves Y 63 into the pumpbarrel, thence through the outlet valve 65,passage 33, reservoir 26, around the circumference of the distributingvalve 23 into the mixing chamber 32, which it enters in the shape of anextremely thin hollow cone, with walls` only a few thou'- sandths of aninch thick. Here it is met by a hollow cylinder of air with also averythin wall, so that the extremely small globules of fuel becomethoroughly mixed with the air before being brought together in a solidstream at the neck of the carburetor when the complete mixture entersthe intakemanifoldof the engine. l

ln order to adjust the degree of opening of the distributing valve 23, anumber of holes 25 are first drilledand tapped, close together in theside of theV conical casting 25; the y valve 23 is then unscrewed fromits seat the desired amount and a threaded rod 55 is pushed up through aslot 55 (Fig. 8) in the bottom of the bowl l0, and then screwedinto theproper hole in the cone 25. The? end yof the rod 55 is then attached toa spring V56 which is fastened at 57and tends to, as shown in thedrawings, open the valve23 still wider, but is prevented from doingthisby'the trie angular piece 58 (Fig. 9) against which it presses.Since the triangular piece 58 is fastened by the screws 59 to theslidingl carriage 53, it will. now be plain that as the carriage 53 ismoved back and forth, the cone 25'and valve 23 will be made to oscillateback and forth and thus detach any grain of dust or foreign 'matter thatmightotherwise tend to stop up a portionof the very narrow passagebetween the valve 23 and its seat. Y

' The inlet valves 63are shown mechanically operated lby means ofthesbell cranks. 68, (Fig. 3) pivoted at 69, operated by valve tappets70, driven by the cam 7l, pinned tothe driving shaft 49. A minute airchamber 75 is drilled into the top Aprojection of the distributing valve23 and communicates with the reservoir 26 by the passage 75. The volumeof this air chamber can be regulated by the long screw 76. s f

An electrical heatinff coil 77 surrounds this upward projection of the'valve 23 with its insulated lead 77 connected with an insulated bindingpost 7 8 in the neck of the carburetor bowl 10. The top and bottom ofthe valve 23 are also shown faced with micaA 78 in order to help throwthe heat derived from the heating coil towards the circumference of thevalve 23 where it warms more or less the fuel being forced between thisvalve 23 and its seat.

In all four cylinder four cycle, combustion engines there is a steadypulsating suction action in the intake manifold varying from practicallynothing toa maximum when one of the engines pistons starts on' itsintake stroke until it reaches about the middle of the stroke. Thevelocity andamount of air being drawn into the intake manifold variesaccordingly as does also the amount of fuel sucked in by the air rushingthrough the ordinary type of carburetor.

In order to duplicate this necessary action I drive the two pumps shownat the same speed as the engine and also synchronize the movement of theplungers with the pistons of the engine. Thus when anengine pistonstarts on its suction stroke one of the twov pumps starts onits'delivery stroke, and thus automatically Vincreases the amount offuel pumped in precisely the same proportion and timeftliat the amountofair is increased thereby keeping constant the percentage of air andfuel during all portions of the suc.-`

tion stroke of the engine. In aDiesel engine the pumps force in fuelduring the power stroke, vand stop Vthis action long before thel enginepistonV reachesthe end of its power stroke and consequently do notoperate in synchronism with the engine pistons.

It is now evident that my charge-forming device produces not onlyanexceedingly intimate mixture of air and fuel, but also breaks up thefuel into exceedingly small globules constituting a genuine mist. Y Italso supplies electrical heat at the proper place tov assist this mistin becoming a gas before it is fired, and furthermore,` when used inconnection with a four cylinder engine, keeps an abso.

lutely constant percentage of mixture during all portions of arsuctionstroke of th-e engine. The resulting effect 1s the complete combustonfofthe fue1ntofGG-a nompoisonousgas.

Itis furthermore practical to voperate-an ordinary vengine over Wide'ranges ofload at constant compression by varying the: stroke ofthepumps and consequently the amount of fuel supplied, without cuttingdown the supply ofair, as is done in the Diesel engine.. f To lever 79,and connect the throttle leven-8()k to the sliding carriage 53, thus4,giving the* operator complete control of both the air and fuelsupply.v .Y f i Fig. 8 shows a slight changein 'the' con# struction ofthe throttleI lever, in order-to compel the operator to changethecompression when vthe engine is idling or running under very lightloads, the rack 8,1 of the lever V79 being attached to and movable withthe'lever 80, so that by moving the lever 80,\the `lever 79 also ismoved, and the butterfly valve 28 f operated simultaneously withtlielcarriage 53. l/Vhen my charge-forming `device is used on a,stationary engine running` at c'onstar'ijt speed under the control `ofalgover'nor, it is only necessary to connectV the governor rod with thesliding carriage vrod 54, adjust lthe butterfly valveV 29 in a permanentposition and run the engi-ne v`under constantcompres-A sion.

nio

Before the 'chargeformingdeviceis put to work it is necessary to pressopen .both the' inlet valve '63 andthe air relief valve^67 ony eachpump. The fuel will then flow inj through they inlet valve 63 and driveout allthe air through tleair relief valve 67 thus completely filling.ther valve chamber and L no It is furthermore necessary to'make.the-Iarea of the opening of the ydistributor valve 23 a trifle smaller thanthe area of the plungerv pump cylinder with the liquid-fuel.

34, in order-to accumulatea slightpressurein the reservoir 26 `and Vthuseause'the fuel `'to spray entirely around the' circumference off thedistributor valve 23. This ipress'ure s will cause avery small amountof'fuel to backfu'p into` the air reservoir 75 which willVtlien be'A iforced lout'by the compressedjair afterv the plunger has finished itsdelivery stroke.

Now since the flow of liquid-fuel is 'apt to be sluggish in gettingAstarted into the pump when its plungerstarts on its suction stroke, Imay set thepumpplu'ngers'slightly in advance of the engine pistons andregulate thexsize of the air reservoir 75 with the screw 7 6, tocompensate for the'rinerti'a effect of the liquid fuer f I VThe fop.part ef Fig. l.ic :Sh-Oase terrien lac section-through themiddle of thefirst cylinder ofa four cylinderV engine. VThe engine piston 93 is shownat top dead center with the connecting rod 91 vertical, theintake valve94 aboutcto open andthe exhaust valve 95 aboutI to close, so that thepiston 93 is about to start into the cylinder on its suction stroke. Thecrank shaft 85, crank pin 90 and the piston pin 92 are consequentlyapproximately in line, as shown.

My ycharge-forming device is shown bolted to the intake manifold 96 ofthe engine by means of the flange 97 in the usualmanner. The shaft 49 ofmy charge-forming device is shown extended so as to reach to the frontpart Y of the engine. The shaft 49 of my charge-forming device isrotatedat precisely the same speed as the crank shaft 85 of the engine.The two eccentrics 47 and 51 rotated by the shaft 49 and fullyillustrated and described -in .the specification and drawings are drawnso as to'throw the rocking forked lever 42 toits extreme position,thereby tilting the walking beam 35 to its extreme position softhat thepump plunger 34 will have entirely completed vits delivery stroke andpump plunger 34 will he just about to start f on its delivery stroke.,-

Assuming that the engine is ruiming and firing l, 3, 4,2, the intakevalve of No. 2 cylinder will vnow be nearly wide open and the air will.be .still rushing through this valve, although the piston in No. 2cylinder will have fully completed its suction stroke. rlhe fuel pump34has also entirely completed its delivery stroke but during thisactionlit has compressed the air in air chamber 7 5- (Figq2) underneaththe distributingjvalve 23, thereby causing Vfuel to be forced throughsaidfvalve 23 into vthe mixing chamber 32, therebysupplying fuel to mixwith the air now rushing into No. 2 cylinder.

vNow, as the piston 93 in No. lk cylinder starts in von its suctionstroke, the'pump plunger 31 of my charge-formingl device starts todeliver fuel underneath the distributing valve 23 and also to helpmaintain the pressure ofthe air inthe air chamber 75. A

supply of fuel isv thus ensured to mix with the air at all times duringthe operation of the engine. The chief advantage claimed'in usingmycharge-forming device over the usual form ofsuction-type carburetor isthat by using mechanicalpower to force the fuel around the periphery ofmy distributing p valve 23, it becomes practical to hold this valve 23adistance of only one or two thousandths of an .inch from its seat,thereby forcibly breaking up the fuel into a mist containing drops offuel very much smaller than is possible when using only the suction pullof the engine cylinder, as is now the usual custom in all commercialtypes of carburetor.

The advantage of breaking up the fuel into extremelyy vfine mist is wellunderstood byall those skilled in the art of designing' car'- buretors.Heavy grades of fuel not capable of self-evaporating into a gas may alsobe used with my charge-forming device. It is evident that in the ydesignsubmitted in the drawings and` specification unlessv the valve 23 islifted an extremely `small distance from its seat the fuel from thepumps 34, 34 will iow freely through and by the valve 23,'so that littleor no compressed air will be stored up in the air chamber 75. Such anadjustment would not only defeat the chief object of my invention, butwould cause an intermittent supplyy of fuel to be delivered to theengine, thereby failing to keep up the proper p-roportion of air andfuel which is the sole function of all practical carburetors.

l In adapting my invention to a six cylinder engine I set the plungersso they will start to pump when the demand forfuel is at a minimum, andby enlarging theair reservoir 7 5 still further, utilize the accumulatedpressure in' the air reservoir to supply fuel when neither pump isdelivering. This arrangement however only approximates the requirementsof the engine, and in order to make my charge-'forming device ideal fora six cylinder engine there should be three pumps set 1200 l. VAforce-feed charge-forming device for supplying fuel to an internalcombustion engine comprising in combination a fuel feed pump, said pumpoperating in synchronism with thepower piston of the internalVcombustion engine to which said device is attached and being so timedthat the delivery stroke thereof begins and'ends simultaneously with thebeginiviingv and ending of the engine'suction stroke, a reservoircontaining a small amount of fuelrelative to the capacity of said pumpand subjected to the pressure of' a conlined gas, and a distributorvalve spaced such a small distance from its seat as to oppose the flowof fuel forced through said valve by vsaid pump and thereby cause thefuel to beV llO so timed that the delivery stroke of each of said pumpsbegins and ends with the beginning and ending of the suction stroke ofthe corresponding power piston, a fuel reservoir of relatively smallcapacity communicating with said pumps and a valve for said reservoirspaced a relatively short distance from its seat.

3. The combination with an internal combustion engine having a powerpiston, of a fuel pump driven in mechanical synchronism with said powerpiston and being so timed that the delivery stroke of said pump beginsand ends with the beginning and ending of the suction stroke of saidpower piston, a fuel` l reservoir, a valve for sald reservolr, the areastroke of said pump, and to deliver the same .y

after the completion of said delivery stroke. In testimony whereof, Ihave hereunto subscribed my name this 21st day of December, 1923. i i

HENRY H. CUTLER.

